Prosecution Insights
Last updated: April 19, 2026
Application No. 18/546,408

DOUBLE-SHELL NEODYMIUM-IRON-BORON MAGNET AND PREPARATION METHOD THEREFOR

Non-Final OA §103§112
Filed
Aug 14, 2023
Examiner
WU, JENNY R
Art Unit
1733
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Fujian Golden Dragon Rare-Earth Co. Ltd.
OA Round
1 (Non-Final)
63%
Grant Probability
Moderate
1-2
OA Rounds
3y 1m
To Grant
80%
With Interview

Examiner Intelligence

Grants 63% of resolved cases
63%
Career Allow Rate
529 granted / 838 resolved
-1.9% vs TC avg
Strong +16% interview lift
Without
With
+16.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
45 currently pending
Career history
883
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
50.5%
+10.5% vs TC avg
§102
12.2%
-27.8% vs TC avg
§112
23.2%
-16.8% vs TC avg
Black line = Tech Center average estimate • Based on career data from 838 resolved cases

Office Action

§103 §112
Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Election/Restrictions Applicant’s election without traverse of Group I, claims 1-2 in the reply filed on 11/11/2025 is acknowledged. Claims 3-10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected group II, there being no allowable generic or linking claim. Status of Claims Claims 1-10 are pending. Claims 1-2 are presented for this examination. Claims 3-10 are withdrawn. Priority Receipt is acknowledged of certified copies of papers submitted under 35 U.S.C 119(a)-(d), which papers have been placed of record in the file. Information Disclosure Statement The information disclosure statement (IDS) was submitted on 12/05/2023, 01/16/2025, 04/21/2025, 07/22/2025, 10/22/2025 and 11/07/2025 and is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-2 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, or for pre-AIA the applicant regards as the invention. The terms “inner layer” and “outer layer” in claim 1 are fundamentally relative terms because the terms “inner” and “outer” depends entirely on the point of reference or the specific system being described. In the instant case, it is unclear whether inner and outer are relative to the core of the shell or the main phase crystal grain. Hence, it renders instant claim indefinite. As a result of rejected claim 1, all dependent claims are also rejected under the same statue. Claim Rejections - 35 USC § 103 The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. Claim(s) 1 is rejected under 35 U.S.C. 103 as being unpatentable over Zakotnik (US20230154657) in view of Zhou (NPL document “Sintered NdFeB magnet with Tb-Dy double layer core/shell structure were fabricated by double alloy method and grain boundary diffusion”) and Liang (NPL document “Coercivity enhancement of Dy-free Nd-Fe-B sintered magnets by intergranular adding Ho63.4Fe36.6 alloy”). As for claims 1-2, Zakotnik discloses in Figure 1 below a double shell NdFeB magnet comprising: PNG media_image1.png 560 1030 media_image1.png Greyscale G2Fe14B core wherein G is a rare earth element, for example Nd ([0057]). Hence, G2Fe14B core meets instant claimed main phase crystal grain comprising R2Fe14B where the R is Nd Exemplary Element 1 shell reads on instant claimed double shell has an inner layer Exemplary Element 2 shell reads on instant claimed double shell has an outer layer The G2Fe14B core is surrounded by a thinner Nd rich phase that coats each core grain and is knowns as the grain boundary. ([0114]) Hence, the thinner Nd rich phase reads on instant claimed Nd rich phase adjacent to the main phase crystal grain. The double shell has a thickness of 0.5-1 microns. ([0179]) Hence, instant claimed thickness 0.1-6 microns is met. The thinner Nd rich phase is made of grain boundary magnet (GBM) alloy metal represented by a formula NdjDykComCunFep, wherein j, k, m, n and p each represents atomic percent. ([0027]) Within the formula, Nd reads on instant claimed R, Dy reads on instant claimed RH, Co and Fe reads on instant claimed T and Cu reads on instant claimed X. Since atomic percent j is 6-7 ([0028], k is 5-10 ([0029]), m is 1-5 ([0030]), n =12 to 14 ([0031] and P is 13-14 ([0032]), instant claimed Nd-rich phase comprises (R-RH)6T13X is met. Zakotnik does not disclose the outer layer comprising (Nd/Dy)2Fe14B and/or (Nd/Tb)2Fe14B and the inner layer comprising (Nd/Ho)2Fe14B and/or (Nd/Gd)2Fe14B. Zhou discloses a sintered NdFeB magnet with Tb-Dy double layer core/shell structure were fabricated by double alloy method and grain boundary diffusion. Zhou explicitly discloses formation of high magnetrocystalline anisotropy of (Nd,Dy)2Fe14B and (Nd,Tb)2Fe14B as double layer core/shell structure can greatly improve the coercivity of sintered NdFeB magnets. That is, Zhou suggests double shell having two layers which one layer comprising (Nd, Dy)2Fe14B and another layer comprising (Nd,Tb)2Fe14B. Liang further discloses that due to expensive and scare heavy rare earth element Dy, heavy rare earth element such as Ho, which is only one fifth the cost of Dy, has been developed to substitute Dy usage. By developing a Dy-free Nd-Fe-B sintered magnets, a (Nd,Ho)2Fe14B shell is formed in the outer region of main phase grain. (Abstract) Hence, it would have been obvious to one skill in the art, at the time the invention is made to, substitute (Nd, Dy)2Fe14B with (Nd, Ho)2Fe14B , in the NdFeB magnet of Zakonik in view of Zhou to arrive claimed double shell having an inner layer comprising (Nd, Ho)2Fe14B and an outer layer comprising (Nd, Tb)2Fe14B because Liang discloses Ho is more cost effective than Dy. Claim(s) 2 is rejected under 35 U.S.C. 103 as being unpatentable over Zakotnik in view of Zhou and Liang as applied to claim 1 above, and further in view of Hirota (US20170140856). As for claim 2, neither Zakotnik, nor Zhou or Liang disclose presence of ZrB2 and TiB2 in Nd rich phase. Hirota discloses Nd-Fe-B sintered magnet having a Nd rich phase comprising thermodynamically more stable boride such as TiB2 and ZrB2 as effective elements for inhibiting abnormal grain growth of main phase grains during sintering. ([0039]) Hence, it would have been obvious to one skill in the art, at the time the invention is made, to include TiB2 and ZrB2 as suggested by Hirota, in the double shell Nd-Fe-B magnet of Zakotnik in view of Zhou and Liang because Hirota discloses TiB2 and ZrB2 provides the benefit of inhibiting abnormal grain growth of main phase grains during sintering. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to JENNY R WU whose telephone number is (571)270-5515. The examiner can normally be reached on 8:30 AM-5:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith Hendricks can be reached on (571)272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /JENNY R WU/Primary Examiner, Art Unit 1733
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Prosecution Timeline

Aug 14, 2023
Application Filed
Dec 01, 2025
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
63%
Grant Probability
80%
With Interview (+16.4%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 838 resolved cases by this examiner. Grant probability derived from career allow rate.

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